Mobile satellite services, including satellite radio services, employ a variety of techniques to supplement satellite based signal coverage. For example, since satellite based signal may degrade in high density/high rise building areas, the satellite radio services, such as XM and SIRIUS, employ a network of terrestrial repeaters that operate within the satellite radio service band to supplement satellite based coverage.
The XM satellite service band, for example, occupies 12.5 MHz of spectrum in the mid-2 GHz frequency range. The XM spectrum is split between satellite and terrestrial repeater operating bands. The frequency bands for the satellite and terrestrial signals are adjacent within the allocated 12.5 MHz of spectrum, thereby raising the need to control the possibility of adjacent channel interference between the satellite and terrestrial based signals at the receiver when the subscriber's vehicle travels from an area covered only by satellite signals to an area where both satellite and terrestrial coverage is available. The satellite band signal gain may be reduced to reduce the chances of the adjacent channel interference. However, this leads to a decreased service footprint in areas where only satellite coverage is available when satellite reception degrades due to dense foliage, for example. Therefore, a need exists for a mechanism to dynamically control the possibility of adjacent channel interference between satellite and terrestrial based signals while enhancing the satellite reception in areas not covered by the terrestrial repeater network.